1. Field of the Invention
This invention relates to processes for preparing 1H-imidazo[4,5-c]quinolines. In another aspect this invention relates to processes for preparing 1-substituted-1H-imidazo[4,5-c]quinolin-4-amines.
2. Description of the Related Art
The synthesis of 1H-imidazo[4,5-c]quinolin-4-amines has been described in U.S. Pat. Nos. 4,689,338 (Gerster) and 4,929,624 (Gerster et al.). The methods described therein involve the step of heating the 4-chloro compound in the presence of ammonium hydroxide or ammonia under pressure (e.g., in a sealed reactor) to afford the 4-amino compound.
Khim. Geterosiklicheskikh Soedinenii 1976, 2, 229 (Solekhova et al.) describes the amination of pyridine N-oxide and quinoline N-oxide at the 2-position with ammonia and some ammonia salts in the presence of p-toluenesulfonyl chloride. Similarly, Chem. Pharm. Bull. (Tokyo) 1984, 1, 35 (Hamana et al.) describes the reaction between quinoline 1-oxide and various amines in the presence of an acylating agent.